Servers are core components for serving computers in a network system. Servers provide a variety of functions for network users, including storage and sharing of resources within a server system. Servers generally contain an architecture with a central processing unit, a memory, one or more hard drives, and other components which are connected through a bus. In general, a server system can consist of one or more server racks and a number of server blades, sleds, or chassis insertable into slots or locations in the server racks that physically supporting one or more servers or other type of computing devices. Typically, the racks and the chassis are designed according to unified international cabinet standards. That is, the physical specifications for the racks and chassis are based on agreed-upon standards. In this way, the configuration, assembly, and management of a server system is convenient and standardized.
Locations within a rack are generally classified according to a standard unit of height for the chassis or multiples thereof, such as 1U, 2U, 3U, etc. Thus, a chassis is referred to as a 1U chassis, meaning that it is one rack unit in height. A 2U server consumes two rack units of space within the rack. In addition to such standard height configurations, there are also standard width configurations for the rack, define by the width of the locations in the rack and accounting for any sliding rails or other attachment devices for attaching the chassis to the rack. Thus, the width dimensions of the chassis are generally constrained by the dimensions of the server rack and the attachment devices.
Typical server cabinets provide hard drive modules which allow for multiple hard drives to be disposed in a portion of a chassis along its width. However, these hard drive modules are generally constrained by the width dimensions of the chassis. This limits the amount of hard drives which will fit inside of the chassis, and thus the hard drive capacity is fixed.